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Posse Comitatus in Space: Forging a Relationship between the US Space Force and Law Enforcement

  • Published
  • By Capt Glenn Germany, USSF


The Posse Comitatus Act1 and additional federal law2 prohibit the use of the Army, Air Force, Navy, and Marine Corps to execute laws in the United States. In stark contrast, the US Coast Guard (USCG) possesses law enforcement capabilities and responsibilities “upon the high seas and waters over which the United States has jurisdiction, for the prevention, detection, and suppression of violations of laws of the United States.”3 As the Department of Defense continues its stand up of the US Space Force (USSF), Congress must draft legislation similar to that pertaining to the USCG to allow local law enforcement agencies to use USSF assets, specifically surveillance satellites, in their investigations and reconnaissance. With the increase in commercial space operations and advancement of technology we see every day, the USSF will need the flexibility to enforce laws in space as well as help law enforcement agencies from space with its assets in place.

Expansion of Space Tourism Signals a Need for Law Enforcement Body Now

Space is the final frontier, and it holds countless opportunities for exploration and recreation. There are a number of private entities, i.e., SpaceX4 and Virgin Galactic,5 that have aims to send civilians to space, creating a new form of entertainment known as space tourism. Although civilian orbital sojourns are exorbitantly priced and rare to launch at present, the trend is a message to regulators that there will be a time in the not-so-distant future that space needs not only regulations but also an entity such as the USSF to help enforce those regulations.

Critics might argue that it is premature to give any sort of law enforcement capabilities to this brand-new branch, but acting now will save time and allow a federal agency to enforce regulations when necessary. The USCG law enforcement powers were granted by statute in 1949,6 a time when the focus of homeland defense was against foreign states, not foreign drug cartels. However, because the law enforcement powers were broadly granted to the USCG, its role has been able to evolve as the threat has changed. Now a primary mission of the USCG is drug interdiction,7 which would not have been possible had legislation not given the USCG law enforcement powers. Congress would have had to pass new legislation granting law enforcement powers to the USCG while a valuable asset sat idly by and may not have even joined the law enforcement team. Though the Outer Space Treaty8 grants the exploration and use of outer space to all countries, there will come a time when sovereign nations and bad actors will use space to harass and injure other states. This will, in turn, push nation-states to redefine jurisdiction between airspace and space to allow better security for all. Granting broad law enforcement powers to the USSF similar to the USCG now will ensure there is an enforcement body in space before space becomes more public, thus, enabling regulators to monitor and control space actions over the United States before technology, practices, and law get ahead of law enforcement.

The Public Debate Concerning Government Satellite Surveillance

With regards to the USSF aiding local law enforcement agencies in surveillance, the debate over using government satellite equipment for law enforcement purposes is not a new one. As recently as 2007, the Department of Homeland Security was looking to aid law enforcement from space. In that year, Congress funded a program known as the National Applications Office, a sort of go-between for law enforcement and federal spy agencies. If it were implemented, civilian law enforcement agencies would be able to request satellite imagery from America’s spy agencies for their investigations, similar to the Civil Applications Committee that enables agencies to request spy imaging for environmental and scientific study.9 Eventually the National Applications Office lost steam, and the program was abandoned due to congressional concerns over protecting civilian privacy.10 Several Democrats decried the office, though some did state in a memo to then-Secretary of the Department of Homeland Security Michael Chertoff that they supported “any Department effort to engage in more effective and responsive information sharing with our nation’s first preventers.”11

Privacy and the Plain View Exception to the Fourth Amendment

Although privacy arguments will still be made by opponents to the USSF sharing resources with local law enforcement, a review of current jurisprudence shows that the US Supreme Court would find that satellite imaging would fall under the plain view exception to the Fourth Amendment prohibition on warrantless searches because society is willing to accept the fact that people do not have an expectation of privacy from satellite surveillance.

California v. Ciraolo12

In one of the first cases the US Supreme Court reviewed in regards to aerial surveillance, California v. Ciraolo, the test of privacy in regards to the Fourth Amendment was addressed. In Ciraolo, local law enforcement applied for and obtained a search warrant based on aerial observation of a suspect’s backyard from an airplane flying 1,000 feet over the suspect’s home.13 The Court, citing Katz v. United States,14 applied a two-part test to determine whether aerial observation could fall under the plain view exception to the Fourth Amendment protection against warrantless searches and seizures: “first, has the individual manifested a subjective expectation of privacy in the object of the challenged search? Second, is society willing to recognize that expectation as reasonable?”15

The Court found the suspect did have a subjective expectation of privacy shown by the fences erected in the backyard, and the Court quickly turned to the second question of the test. When considering society’s willingness to accept the expectation as reasonable, the Court asked “whether the government’s intrusion infringes upon the personal and societal values protected by the Fourth Amendment.”16 Because any civilian could have seen what these officers saw in public airspace, the Court ruled society was not prepared to honor the expectation of privacy.17

Dow Chemical Company v. United States18

The US Supreme Court decided another aerial plain view case the same year as Ciraolo in Dow Chemical Company. Although different from a Fourth Amendment search, given the corporate nature of Dow and the rights a corporation possesses, the Court made a statement, in dicta, with regards to highly sophisticated photography equipment. When Dow argued that the government utilized cameras not readily available to the public, the Court dismissed the argument but added the caveat that “surveillance of private property by using highly sophisticated surveillance equipment not generally available to the public, such as satellite technology, might be constitutionally proscribed.”19

Kyllo v. United States20

Another applicable case when considering satellite imaging is Kyllo, wherein the US Supreme Court considered whether government agents could use thermal-imaging devices to take heat signatures from inside a suspect’s home without a warrant. An arrest was made based on observations that indicated heat lamps were being used illegally to grow marijuana. The Court concluded because law enforcement used “a device that is not in general public use, to explore details of the home that would previously have been unknowable without physical intrusion, the surveillance is a ‘search’ and is presumptively unreasonable without a warrant.”21

Today’s Application

In today’s world the question of whether satellite imagery falls under the plain view doctrine will be two fold. First, if an individual claims an expectation of privacy from satellite surveillance, is society willing to accept that expectation as reasonable? Second, what level of photography sophistication is too advanced as to render a search unlawful?

With regards to society’s view of searches from space, it is clear that satellite imaging is a common and accepted practice. With the advent of private corporation mapping (i.e., Google and Apple Maps) as well as imaging from these companies where an individual can see the shape and size of buildings, the individual plants in a backyard, and the cars parked in a driveway, it has become commonplace for an individual’s belongings and property to be on display for free to society as a whole. If law enforcement were to get images from the USSF showing the same things from a corporate entity, a court would be hard pressed to find that society still accepts this expectation of privacy from satellite images. As the Supreme Court stated in Katz, “What a person knowingly exposes to the public, even in his own home or office, is not a subject of Fourth Amendment protection.”22 Society is increasingly exposing things that it knows can be seen from space through satellite surveillance, and thus, satellite imaging should not be afforded Fourth Amendment protection.

Further, space will soon welcome private citizens in the space tourism industry. In the not-so-distant future, space will be considered a public space, while Joe Public will have the ability to view into another’s backyard similar to citizens in planes in the 1980s akin to the Ciraolo case. It is unlikely it would be reasonable for society to accept that expectation of privacy.

Some will ask why a military body should be given this authority when private companies take the same images. A litany of arguments can be made for either side, but a key distinction would be government imaging is presumed to be reliable. A corporation has competitors and vulnerabilities that make it susceptible to altering and cyberattacks. Whereas a military body will have squadrons devoted to the protection of the networks and systems that generate the images. Critics will also point out that the National Reconnaissance Office (NRO) already provides these images through their assets, thus negating the needs for the USSF to have similar powers. While this article acknowledges the role of the NRO in some local law enforcement activities, the scope of this article is solely on why the USSF, specifically, needs law enforcement powers as well.

As technology advances courts will have to determine what constitutes an invasion into the sanctum of one’s home. Currently, without a warrant, law enforcement cannot use technology that penetrates the walls of a home, such as audio eavesdropping, thermal imaging, and other such devices. Military satellites have tremendous capabilities beyond what is available to the public, and these abilities should not be employed for law enforcement purposes. Society is not ready to give full access to their homes over to the government. However, high-definition cameras and other imaging technologies that are used by both the military and private corporations should be allowed, as society would not support a claim of privacy from this type of search.

Regardless of what society currently thinks is reasonably private or not, Congress needs to draft legislation allowing the Space Force the ability to assist law enforcement similar to the USCG. As technologies advance, society will become more accustomed to space assets viewing their backyards and other properties and will no longer be willing to accept an individual’s assertion to privacy in those areas. If these provisions are not enacted in the initial stages of standing up the USSF, Congress will have difficulty enacting them later, as illustrated by the case of the National Applications Office in 2008. Congress must provide legislation to have better information sharing between the USSF and the nation’s first preventers.

Capt Glenn Germany

Captain Germany (BA, Brigham Young University, 2008; JD, Santa Clara University School of Law, 2011) is an assistant staff judge advocate and currently serves as the Chief of Operations Law at Peterson AFB, Colorado. Prior to joining the USAF, Captain Germany worked as a criminal prosecutor in California for six years. His children constantly ask him if he will be the first JAG to fly in space as part of the United States Space Force.


1 US Code, vol. 18, sec. 1385 (1956).

2 US Code, vol. 10, sec. 275 (1981).

3 US Code, vol. 14, sec. 522 (1949).

4 Tariq Malik, “SpaceX Will Fly Space Tourists on Crew Dragon for Space Adventures,”, 18 February 2020,

5 Darrell Etherington, “Virgin Galactic Becomes the First Public Space Tourism Company on Monday,” TechCrunch, 24 October 2019,

6 US Code, vol. 14, sec. 522 (1949).

7 US Code, vol. 6, sec 468 (2002).

8 “Treaty on Principles Governing the Activities of States in the Exploration and Use of Outer Space, including the Moon and Other Celestial Bodies,” entered into force: 10 October 1967, United States Treaties, volume 18, sec. 2410.

9 Robert Block, “U.S. to Expand Domestic Use of Spy Satellites,” Wall Street Journal, 15 August 2007.

10 Department of Homeland Security, Secretary Napolitano Announces Decision to End National Applications Office Program, 23 June 2009.

11 House Committee on Homeland Security to Michael Chertoff, Secretary of Homeland Security, memorandum, 7 April 2008.

12 California v. Ciraolo, in United States Supreme Court Reports, vol. 476 (1986), 207.

13 Ciraolo at 209–210.

14 Katz v. United States, in United States Supreme Court Reports, vol. 389 (1967), 347.

15 Ciraolo at 211.

16 Ciraolo at 212.

17 Ciraolo at 214.

18 Dow Chemical Company v. United States, in United States Supreme Court Reports, vol. 467 (1986), 227.

19 Dow Chemical Company at 238.

20 Kyllo v. United States, in United States Supreme Court Reports, vol. 533 (2001), 27.

21 Kyllo at 40.

22 Katz at 351.

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